Vespa G.S. 150
The Gran Sport, or "G.S." 150 was unveiled in 1955, and blended style and speed. The G.S. wasn't the first luxury or sporting scooter, but it was the first to achieve mass market success. It opened the door for the many models and makes of scooters which followed its footsteps.
There were several versions of the G.S. 150 made. They are commonly referred to by the beginning of the frame number on the scooter. The first G.S.'s frame number began at VS1 in 1955, and the last ended with VS5 in 1961.
The G.S. represented a substantial upgrade from the truly utilitarian Vespas which preceded it. Indeed, Piaggio had introduced a 150cc version of the Vespa in 1954, but the G.S. 150, began in 1955, was something else entirely. In the U.S., I'm not sure exactly when G.S.'s were first imported to the U.S.. I have seen a handful of VS4's, and quite a few VS5's. If Piaggio imported VS3's, it was not in significant numbers. I do not believe that any VS1 or VS2 were originally sold in the U.S.
The styling of the G.S. is, without doubt, the pinnacle of Piaggio's scooter design. In my opinion, the body design has never been equaled by any other scooter to leave the Pontadera factory. When you look at it, especially on the later versions which had enclosed cables, it is a smooth and integrated design. It is indeed the height of form and function. As described with the motor above, the G.S.'s styling was everything that the Vespa 150 was, but more. The body was physically bigger, and the cowls' curves were exaggerated and made even more round than those on the Vespa 150. In fact, from the sloped tail to the curved legshields, there is hardly a straight line anywhere on the scooter. Even the floorboards on the G.S. are concave. As on the standard Vespa, the left side cowl was the glovebox, but on the G.S., it also housed a special slim battery and electrical regulator rectifier which were unique to this model. The small space under the gas tank which on the standard Vespa housed the carburetor was retained on the G.S. Now empty save for the fuel filter, it could be accessed through the small underseat door, and also be used for storage. All G.S. 150's came only in metallic silver paint. The horn was of a different design than that on the standard Vespas, and had a stylish shell shape. This horn was later used on many other Vespas.
The handlebars on the G.S. were enclosed and were aerodynamically styled, as opposed to the exposed chrome handlebars on the Vespa 150. On all the models after the VS1 in 1955, the control cables were totally enclosed in the headset. A version of this headset would later be used on all Vespas after 1958. Also on the headset was an integrated ignition switch, another "luxury" item which was only available on the G.S. at the time of its launch. However the switch's utility was greatly diminished by the fact that all GS's used the same blank key! A speedometer was also standard equipment on the G.S. Early versions had a large square speedometer, while the VS5 had the "clamshell" shaped speedometer that was later used on all largeframe Vespas through the late 1960's.
The taillights on the VS1-3 were small and square. The taillight on the VS4 and early VS5's was the two lens "acorn" type used on the Vespa 150 which had a red taillight on bottom and an orange stop light on top. On the last VS5's, the taillight was the single lens "acorn" type which had a red lens for both the taillight and stoplight. On the late single lens type, a small reflector was located in the lens. The seat on the G.S. was a dual saddle with which is slightly wider at the front and narrower at the back. The seat included a grab strap for the passenger and was black in color.
Though based on the Vespa 150 motor design, the G.S. was tweaked in several important ways to increase its speed and sporting characteristics. Most obviously there was a four speed gearbox, a first for a Vespa. Inside, the compression was raised, and the piston crown was changed to a more efficient a domed type. The carburetor was increased to a 23mm unit and a larger exhaust was added to help the motor breath. The clutch was also upgraded to handle the increased power. These changes, along with altered cylinder porting and other internal modifications, allowed the G.S. to put out 8 horsepower, as opposed to 5.4 from the Vespa 150 - a major increase considering the two motors had the same displacement. The top speed was around 65 miles per hour. All of the G.S. 150's had a battery assisted spark system. This system requires a functional battery for the bike to run. Previously out of production, the original-style battery is now being reproduced, but is very expensive.
On the handling side, the G.S. was improved over the standard 150 with the addition of 10" wheels and larger brake shoes. On the VS1-4, the wheel rims had four large lugs in the center of wheel. On these models, the brake drum is behind the wheel. On the VS5, the brake drums were modified to allow for better cooling. On that model the wheel drum was integrated into the wheel design, and the actual rim attached at the outside of the drum rather than over the drum as on the earlier models. This system was a big improvement as it helped cool the drums and allowed for improved braking with less fade. This design remained virtually unchanged through the last PX200E's, and is actually still being manufactured.
Although the G.S. is the quintessential Vespa in design terms, there are not as many on the road as one might expect - especially in the U.S. Many broke down because someone didn't realize that the motor required a massive 6% two stroke oil mixture, and seized the piston. Others were tossed aside as non-runners because the battery died, and a later owner had no idea that the ignition required the battery to work. Furthermore, the scooter used a specialized 12 amp battery which was not available for many years. Rust can be a real problem on all of the G.S.'s as well, due to the concave curvature of the floorboards which traps and pools water. The early models of the G.S. are highly sought after. Finding a VS1 or VS2 outside of a serious collector's hands is unlikely.
As with all of the pre-60's Vespas, it is important that you find a G.S. that is complete. Some of the internal wear parts for the motors are now being reproduced, but not much else that is unique to the G.S. is available. The motors changed slightly with each incarnation, and some motor parts on the GS150's are very difficult to source, make sure your motor is all there before you buy one. Body parts are also quite hard to come by, especially in the U.S. Expect that any missing part, even something that is seemingly small, will take a long time and a lot of money to obtain.
When looking at a potential GS purchase, pay careful attention to the condition of the motor. As mentioned above, all versions have similar motors, but they all are very difficult to source parts for. They are also not easy to work on. This is especially true for a mechanic who is not familiar with their peculiarities. Therefore you can expect that if you are fortunate enough to have a shop willing to work on your G.S. motor, it will be expensive. Unless you are an experienced scooterist or mechanic, it is wise to shy away from a "project" GS. The cost of restoring one can quickly exceed the cost of buying one that is already in good condition
Nevertheless, the G.S. is a wonderful machine to drive. It is very nimble and fast. Even now, 50 years from its debut, comports itself well on today's roads. The design was so far ahead of its time, that it still looks fresh, and its "sporting" motor is fast enough to keep up with modern traffic. As the owner of a G.S. 150 VS5, I can truly say that this scooter is a delight to drive. It is very quick and handles well.
- Rough but restorable = $800-1500
- Drivable, but not show = $2500-3500
- Restored or Excellent Original Condition = $4000-8000
Note: The guide above is for VS4-5. Pre-VS4 G.S.'s are very rare, and command a price premium.